This is the main and possibly most interesting feature of AppMgr III (App 2 SD). It allows you to free up memory space by storing files on your SD card. There are also some other useful features that will help you batch install and uninstall apps (using APKs). That means that you could, for example, quickly install three or four games with just a tap.
Another intriguing feature allows you to hide system apps that you never use but normally cannot erase. All that it does is hide the icon so you don't have to see it anymore, but that's still pretty nice.
AppMgr III (App 2 SD) is a useful tool for managing apps on your Android device. Its interface may not be completely intuitive, but it gives you everything you need within a pretty attractive format.